利用高分辨率光谱和从头算理论研究9-甲基蒽的大振幅运动

本文利用平行超音速射流和光频梳技术观察到9-甲基蒽(9MA)的多普勒的高分辨率和高精度光谱. CH₃内部旋转的势能曲线用六重对称正弦函数表示. 之前报道的9MA-d12的势垒(V₆)远远低于9MA-h12M. Baba, et al., J. Phys. Chem. A 113, 2366 (2009)]. 本文对多组分分子轨道法进行从头算方法的理论计算. 氘代取代势垒降低的部分原因是H和D原子核的波函数不同.

Large Amplitude Motion in 9-Methylanthracene: High-Resolution Spectroscopy and Ab Initio Theoretical Calculation

CH₃ internal rotation is one of the typical large amplitude motions in polyatomic molecules, the spectral analysis and theoretical calculations of which, were developed by Li-Hong Xu and Jon Hougen. We observed a Doppler-free high-resolution and high-precision spectrum of 9-methylanthracene (9MA) by using the collimated supersonic jet and optical frequency comb techniques. The potential energy curve of CH₃ internal rotation is expressed by a six-fold symmetric sinusoidal function. It was previously shown that the barrier height (V₆) of 9MA-d₁₂ was considerably smaller than that of 9MA-d₁₂ M. Baba, et al., J. Phys. Chem. A 113, 2366 (2009)]. We performed ab initio theoretical calculations of the multicomponent molecular orbital method. The barrier reduction by deuterium substitution was partly attributed to the difference between the wave functions of H and D atomic nuclei.